Description:
------------
affects runkit 0.9:

I'm using runkit_function_redefine to redefine a system function (passthru). I would like to be able to intercept the parameters passed to this function in old_passthru.
For some files, the code bellow is working great. 

However, if you have an PHP file with any function defined, runkit returns an Fatal error: Cannot redeclare my_function().
If the function is commented out, it's working fine.


Reproduce code:
---------------
File /var/www/tr/index.php
---------------
<?php

function my_function() {
}	
	
// redefine passthru
runkit_function_copy('passthru','old_passthru');
runkit_function_redefine(
'passthru',    // function to redefine
'',			   // number of parameters		
			   // code	
'
$args = func_get_args();
echo "<b>passthru</b> params = [<b>" .  func_get_arg (0) . "</b>]<br>";
return call_user_func_array("old_passthru", $args);
'
);

// call passthru
passthru("ls");

?>

<i><br>
this is html already
</i>	


Expected result:
----------------
passthru params = [ls]
index.php phpinfo.php runkit.php
this is html already

Actual result:
--------------
Fatal error: Cannot redeclare my_function() (previously declared in /var/www/tr/index.php:4) in /var/www/tr/index.php on line 4